Ocean Acidification in a General Chemistry Laboratory Experiment: Scientific Data and Indigenous Knowledge

This page authored by Jessica Pikul, Ph.D., South Seattle College. Laboratory based on the work of Buth, J M. at the University of Mount Union published in J Chem Ed. 2016, 93, 718-721.

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Initial Publication Date: June 19, 2024

Summary

Students explore the effects of ocean acidification by measuring the mass loss in seashells and the calcium ion concentration in seawater. Alongside data collection during a series of laboratory sessions, students learn about the disproportionate effects of ocean acidification on indigenous livelihoods, food security, and cultural practices, as well as how indigenous knowledge and practices can be used to address acidification locally. The activity ends with students composing an email to an elected official in which they express their opinion about the issue using claim–evidence–reasoning formatting.

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Learning Goals

1. Use le Chatelier's principle to explain how a decrease in pH can affect CaCO3 solubility.

2. Determine the amount of seawater in a sample after a serial dilution.

3. Perform a complexometric titration to calculate the concentration of calcium ions in a sample of seawater.

4. Represent results, and express relationships between them, in a data table that compares calcium ion concentration, pH, and mass% seashell loss in carbonated and non-carbonated seawater.

5. Identify groups that will be disproportionately affected by ocean acidification and climate change.

6. Describe how indigenous knowledge can be used to improve shellfish growth by creating clam beds.

7. Explain the effects of ocean acidification on seashells using lab results as evidence.

8. Express scientific conclusions in a persuasive letter to a public representative using claim–evidence–reasoning formatting.

9. Reflect on and share reactions and feelings about contacting an elected official.

Context for Use

I use this activity in the third quarter (term) of a three-quarter-long General Chemistry series at a two-year college with a class size of 24 students. This course is taken by students majoring in a STEM discipline. A laboratory experiment that spans four laboratory sessions is the centerpiece of this activity. My laboratory sessions for this course are two hours and twenty minutes long, twice per week, but the activity could be adapted to lab sessions of different lengths by combining some of the steps or breaking them up into even smaller steps. I implement the activity over the course of two weeks, and it begins during the third week of a ten-week-long term. This activity is challenging for General Chemistry students at my college, particularly the titration and serial dilutions, so the entire activity would likely be too difficult for high school, but if students focused only on measuring mass and pH, it would work. The activity could also be done at a four-year college or university where class sizes are much larger and laboratory sessions are often taught by graduate teaching assistants, especially if the peer review of post-lab reports and in-class support for letter writing were modified, shortened, or omitted. Prior to encountering this activity, students should be familiar with mass percent, concentration and how to calculate molarity, dilution calculations, solution chemistry, acid-base titrations, acid-base chemistry, equilibrium chemistry, and solubility and solubility product constants. (Although, it is possible to implement the activity concurrently with an introduction to solubility and solubility product constants.) It also helps, but is not necessary, if students are familiar with transition metals (specifically coordination complexes), complex ions, multidentate ligands, and formation constants. The equipment and other materials needed for the laboratory experiment are listed in the laboratory experiment handout. The list includes materials that most college laboratory programs will already have available, but also includes materials that may need to be acquired (i.e., ethylenediaminetetraacetic acid (EDTA), hydroxynaphthol blue indicator dye, a source of carbon dioxide gas, seashells, and seawater). I use the Canvas online LMS to distribute some assignments, collect student work, and offer feedback on assignments, but the use of an LMS is not necessary and, instead of using an LMS, you could print out assignments for distribution to students during class, collect assignments completed by students on paper during class, and provide written feedback on each assignment.

Description and Teaching Materials

The laboratory experiment that is the centerpiece of my activity is a complexometric titration done with ethylenediaminetetraacetic acid (EDTA) and an indicator dye requiring a serial dilution, in order to determine the calcium (II) concentration in seawater. This experiment builds off the work of others who have previously published their work in the American Chemical Society's Journal of Chemical Education. In 2014, Perera and Bopegedera published a laboratory experiment for undergraduate chemistry that uses powdered calcium carbonate, in water adjusted to desired pH levels using buffer solutions, to investigate how solution pH impacts calcium carbonate dissolution, multiple equilibria in solution, and Le Chatelier's principle (Laboratory Experiment Investigating the Impact of Ocean Acidification on Calcareous Organisms). In 2016, Buth adapted this laboratory experiment to use seashells as well as artifical seawater, into which carbon dioxide gas was bubbled to simulate the pH of an acidified ocean, for an analytical chemistry course (Ocean Acidification: Investigation and Presentation of the Effects of Elevated Carbon Dioxide Levels on Seawater Chemistry and Calcareous Organisms). Buth's experiment involves the measurement of carbonate, bicarbonate, calcium (II), and magnesium (II) concentrations. I simplified and modified Buth's laboratory experiment for an introductory chemistry course taken by students intending to major in a STEM discipline (General Chemistry). I focused the experiment only on the measurement of the calcium (II) concentration. I also used real seawater from the Puget Sound, Washington state, USA and carbonated the seawater with a soda stream to simulate the pH of an acidified ocean. (In lieu of a soda stream, a pressurized tank of carbon dioxide gas or dry ice might work.) My students obtained similar calcium measurements as Buth's students did, which gives me confidence that I was able to reproduce his work.

Here is the laboratory experiment handout for students, which I refer to throughout this section:

Ocean Acidification Laboratory Experiment.docx (Microsoft Word 2007 (.docx) 357kB Jun18 24)

Here is the laboratory preparation sheet, which contains all of the details for you, as instructor, regarding the sequence of implementation, expected results including photos, safety precautions, details about waste disposal, and a comprehensive list of materials and equipment. If you have the support staff, such as a Lab Manager, you can share this preparation sheet with that person, so that they know what to set up, what chemicals or equipment might need to be purchased, and how to dispose of waste:

Laboratory Preparation Sheet.docx (Microsoft Word 2007 (.docx) 3.8MB Jun17 24)

Instructor Class Preparation: Check links to the documentary and all videos, acquire all physical materials (e.g., chemicals, equipment) needed for the laboratory experiment (see laboratory experiment handout), prepare the laboratory experiment handout, plan how you will distribute and collect the pre-lab assignment and post-lab report from students, prepare any PowerPoint presentations that you would like to show during class time

Step 1. Introduction to Ocean Acidification (30 minutes). Students watch The Olympic Coast as a Sentinel, which is a 20-minute-long documentary that explains how Olympic Coast tribes living along the coast of Washington state are experiencing climate change, specifically impacts on First Foods as a result of ocean acidification and sea level rise. These tribes have depended on local marine species for their livelihoods, food security, and cultural practices for thousands of years and all are at risk as a result of ocean acidification. After students watch the documentary, I ask them to take three minutes to quietly reflect, on their own, about their initial reaction to the documentary, their thoughts about any one specific part of the film, and also their answer to this question: How are the effects of ocean acidification disproportionately felt by indigenous communities? After thinking about this on their own for a few minutes, they share their impressions with a small group of students. (I encourage groups of 2 to 3 students.) This part of the activity can be done as described during class time, or if you want to implement this step asynchronously and online outside class time, then you could create a discussion board (in Canvas or another LMS) where students can post their initial reaction and thoughts and then respond to one or more students' posts.

Step 2. Ocean Acidification Laboratory, Part 1: Preparing Samples (15 minutes). At the end of the laboratory session for the experiment that precedes the experiment in this activity, students complete a short preparation of two samples of crushed seashells in seawater, one with normal CO2 levels and the second with elevated CO2 levels. For this step, they measure and record the initial weight of two five gram samples of seashells before exposing them to seawater. Then, after recording the initial weights, students put one sample in the non-carbonated water and the other in the carbonated water, and then let them sit for one week on a stir plate to allow reaction to occur. Students work in groups of four for this step, with each group preparing a total of two samples that everyone in the group will use for later steps. This step must be done at least one week before doing Part 2 of the laboratory experiment because the chemical reactions in each sample need time to occur and reach equilibrium. The procedure for this step is described on pages 4 and 5 of the laboratory experiment handout. It is not necessary for students to complete the pre-lab assignment for them to carry out this part of the laboratory experiment.

Step 3: Pre-Lab Assignment (1 to 2 hours). To prepare for the lab, students complete a pre-lab assignment, which is on page 8 of the laboratory experiment handout. For this assignment, I ask students to watch a 12-minute-long lecture about ocean acidification, which I created and recorded. (I also provide, below, the PowerPoint presentation that I show in this video.) The lecture describes the different chemical equilibria present when CO2 gas dissolves in ocean water, in the context of anthropogenic CO2 emissions and climate change, as well as the chemistry behind the impact of ocean acidification on shellfish. The lecture ends with a description of the ways that some tribes and commercial shellfish farmers are addressing ocean acidification, specifically by creating clam gardens or adding soda ash (Na2CO3) to the water. I describe these efforts in the context of chemical equilibria and the solubility product constant for CaCO3, and explain (using Le Chatelier's principle) how the addition of both clam gardens and soda ash to the water increases the pH and helps with CaCO3 shell formation. After the lecture, students watch a seven-minute-long PBS video, Reviving Clam Gardens, that shows how the "Swinomish Tribal Community is reviving culturally and ecologically important clam gardens on their coastline to create habitat for native clams." This video shows how indigenous knowledge can be applied to scientific problems to a similar or better effect. The Swinomish Tribal Community is located near my college. The video describes how "Alana Quintasket, a member of the Tribal Senate, works alongside her community to build these habitats and make the community's coastline more resilient to climate change and encourage healthy ecosystems for marine life." (The sections of the previous two sentences in quotes are from PBS's website. PBS is Public Broadcasting System, an American public broadcast service.) Students will explore this case study more after in Step 6, as they work on their post-lab report after they complete the laboratory activity, but I have them watch the video now so they are familiar with clam gardens as a way to address ocean acidification using indigenous knowledge. After watching the video, students read the introduction and background and the laboratory procedure, found on pages 1 through 7 of the laboratory experiment handout. I also recommend to students that they review titration techniques performed in previous labs. I use lab notebooks for my chemistry course, so I also ask students to prepare their notebook for this lab, according to the guidelines on the laboratory experiment handout. Finally, students answer questions about the chemical reactions and physical changes that will be in equilibrium during their experiment, the chemistry of ocean acidification in general, and clam beds.

Ocean Acidification Lab Lecture.pptx (PowerPoint 2007 (.pptx) 8.1MB Jun17 24)

Step 4. Ocean Acidification Laboratory, Part 2: Mass and pH Data Collection (1 to 1.5 hours).Students complete this part during the next and second laboratory session involving work related to this experiment (the first was the sample preparation described in Step 2). They continue to work in their group of four for this step. During this step, students isolate the seawater by filtering out the crushed seashells and then measure the pH of the isolated seawater. They also rinse shells, allow them to dry overnight, and then measure the mass of the dry crushed shells. The procedure for this step is described on pages 5 and 6 of the laboratory experiment handout.

Step 5. Ocean Acidification Laboratory, Part 3: Ca2+ Titration Data Collection (2 hours). Students complete this part during the last laboratory session that involves work related to this experiment. Students perform four trials of the titration for each sample (non-carbonated and carbonated), for a total of eight titrations. In order for students to carry out all eight titrations and collect all the data needed during one two-hour and twenty-minute-long laboratory session, each group of four students splits into two groups of two students, with one of the new groups of two doing four titrations for the non-carbonated sample and the other group of two doing the titration for the carbonated sample. The groups of two share their data with each other, and with the class as a whole, so that all students have full data sets for their post-lab report (see page 9 of the laboratory experiment handout). The procedure for this step is described on pages 6 and 7 of the laboratory experiment handout.

Step 6. Data Analysis and Post-Lab Report (2 to 4 hours). Between the last laboratory session, described in Step 5, and this step, students complete a draft of their post-lab report. I ask each student to submit their own laboratory report and write their own responses to questions, but I encourage them to work together on the data analysis. For the post-lab report, students analyze data from the laboratory that they just completed (Part 1 of Post-Lab, page 10 of laboratory experiment handout). In addition, each student composes an email to their state representative or the commissioner of public lands about the issue of ocean acidification (Part 2 of Post-Lab, page 11 of laboratory experiment handout).

For Part 1, students create a results table to compare the change in pH, concentration of calcium, and mass % difference for both types of samples (non-carbonated and carbonated) for their group of four, as well as the results for the class. They answer questions that ask them to use their data, as well as multiple chemistry concepts, to explain the effect of increasing atmospheric carbon dioxide on the pH of seawater and the effect of pH on the solubility of the calcium carbonate composing the seashells. They also review the Reviving Clam Gardens video, which they were exposed to in Step 3, to reflect on this method of protecting clams, now that they know more about the chemistry behind clam gardens after completing the laboratory experiment. This video shows how indigenous knowledge can be applied to scientific problems to a similar or better effect. For Part 2, students write their letter to a state representative or the commissioner of public lands using guidelines and a letter writing template that I provide. (I also provide an article How to Message Your Lawmakers by the American Chemical Society as an additional resource.) In their letters, I ask students to express their opinion about ocean acidification (their claim), explain how ocean acidification works, share evidence from this activity (e.g., results of their laboratory experiment, information from videos or readings) to support their claim, and explain how the evidence supports their opinion.

Step 7. Small Group Discussion About Sharing Results With a Public Representative (20 minutes). The next laboratory session, a complete draft of students' post-lab report is due. Students bring their post-lab report (Part 1 and Part 2) to class to participate in small group discussions that involve a peer review and editing process. This process of peer review and editing of post-lab reports is a normal component of my course, early in the quarter when students are first learning how to write these reports. The final version of the post-lab report is then due the next week. Later in the term, students complete post-lab reports on their own, without the peer review and editing process. When discussing Part 1 of the post-lab report, students review class results and share in small discussion groups their thoughts about why clam beds help juvenile shellfish grow. (Prior to or during this session, I provide students with class data.) During this part, I guide groups to discuss le Chatelier's principle and the effects of adding more CaCO3 solid to ocean water in the form of clam beds. I ask students to reflect on the effectiveness of applying indigenous knowledge to mitigate the local effects of ocean acidification. For Part 2 of the post-lab report, students participate in peer review of at least two other students' emails, providing positive feedback and suggestions for improvement. They reflect on and discuss, in small groups, whether they feel prepared to send their letter and, if not, what would help them feel ready. After the small group discussions, students share with the class their readiness to send their letters and discuss any hesitation. This part is important because I find that many students are hesitant or even anxious about sending an email to a public representative. As a result, I do not require students to send their email if they do not want to send it or feel uncomfortable about sending it, but I do ask them why they do not want to send it and to explain the feelings that they have about contacting their public representative. I guide this discussion by interacting with students about their feelings and attempt to build student confidence in contacting a representative. During this class discussion, I remind students that constituent opinion is important to the legislative process or the process of developing policy; hearing from us is how our elected officials learn how to represent their constituents. I tell students that elected officials' offices have aides who take in feedback and share it with representatives, in order to emphasize that public officials have staff hired for this purpose because they both expect to, and are prepared to, hear from constituents. I also let them know that, as students, they are more informed on the topic than most of the public and that their educated opinion has value and that they do not need to be a top expert in the field. (A useful analogy is that you don't have to be a doctor to ask someone to stop smoking a cigarette near a baby.) Finally, I tell them that we are all part of the college community, so even if they are not a citizen of the U.S., it is appropriate to share their opinions with representatives who have the college in their district.

Post-Lab Report & Email Class Discussion.docx (Microsoft Word 2007 (.docx) 17kB Jun17 24)

Teaching Notes and Tips

I obtained the seashells needed for this experiment from a friend who subscribes to a local shellfish Community Supported Agriculture (CSA), through which she receives a delivery of shellfish each month. You can obtain seashells from many different sources, such as a local beach where removal of seashells is permitted, an aquarium store, a grocery store, or a local seafood restaurant willing to donate to you.

I live near a body of seawater called Puget Sound and I obtained my seawater there. If you do not live near a sound or the ocean, you can obtain seawater-like solution from an aquarium store that stocks supplies for saltwater tanks, or you can make your own artificial seawater using the formulation used in Buth's Journal of Chemistry Education paper (Ocean Acidification: Investigation and Presentation of the Effects of Elevated Carbon Dioxide Levels on Seawater Chemistry and Calcareous Organisms) which was originally created, used, and published in 1940 by John Lyman and Richard H. Flemming at the Scripps Institution of Oceanography in La Jolla, California, USA (Composition of sea water, Journal of Marine Research).

This activity helped reinforce transition metals, complex ions, multidentate ligands, and formation constants, which is a set of concepts (often included in the same chapter) near the end of the General Chemistry series that is often covered quickly. I really like that this laboratory experiment offers students more experience with these concepts, which is often not the case in many General Chemistry courses.

My students often struggle with serial dilution, particularly with the calculations, such that I include a substantial amount of background information and support on this technique, and the associated calculations, in the section of the laboratory experiment handout that describes this part of the procedure.

The first time I implemented the lab, some of the titration materials that we ordered, which were needed for students to perform the titration, did not arrive at our college on time. As a result, we had to split the titration between two different laboratory sessions on two different days. This means that students repeated the titration process on the second day, after having learned it on the first day and having time to reflect on their techniques afterward. This allowed them to build their skills and their efficiency with the process, resulting in them feeling more confident as chemists working in a laboratory the second time around. This ended their laboratory experience on a better note than if they had only tried the titration procedure for the first time during a single laboratory session, which is the more typical student experience in chemistry courses. This more typical experience can result in students leaving chemistry lab sessions feeling discouraged, incompetent, and like they are not good at chemistry. Most students don't realize that even experienced professional chemists will not be proficient in the laboratory the first time that they try a new procedure and that laboratory techniques and skills take time to perfect. The materials arriving late was a positive unintended consequence of this laboratory experiment. If your school's laboratory schedule allows (mine does not), I highly recommend spreading the titrations that students do for this activity over two days (e.g., do carbonated samples on one day and non-carbonate samples on a second day).

This laboratory experiment could easily require a formal written lab report. I do not do this, but the complexity of the procedure lends itself well to a written report.

For Steps 6 and 7, students write a letter to a state representative, but they could also write a letter to a county or city representative, depending on what is going on with work on clam gardens or other means for addressing ocean acidification. Before asking students to write letters, you would want to identify the present-day role of each of these levels of governance in this work, so that students can write to a public representative in a way that is meaningful.It can be difficult, in our busy multifaceted roles as college faculty, to stay up-to-date on current events related to an issue. One strategy for staying up-to-date on current events so that you know how to engage a public representative on an issue, which does not take too much time, is to do internet searches for the websites of local non-profits and see what is currently highlighted on their websites, what activities and events they are presently involved in and what they are communicating about. The next step is to check the legislative register to see what is on the docket, what is coming up, and the current status of legislation. You will know what terms to use when you search for types of legislation once you have read the websites of nonprofits and learned what they are working on. I have prior experience representing academic workers in the Washington State Legislature which has informed my strategies to teach students how to engage with elected officials. It is not difficult to learn how to do this type of civic action and I have compiled resources for you, as a faculty member leading this work in your classroom. Writing Elected Officials - Resources for STEM Faculty.pptx (PowerPoint 2007 (.pptx) 2.3MB Jun3 24)

Step 7 is very important, for the reasons discussed under Step 7 in the Description and Teaching Materials section. Because most students have hesitations or even anxiety about contacting public officials, it is especially important to do this part of the activity in-person during class time, as opposed to asynchronously and online where students cannot interact as easily. Having time to talk with other students and the instructor in real-time, during class time, really helps students process their feelings about this and can help them build confidence to actually send the email. In addition to their emotions and hesitations, students are generally very inexperienced with this process (and you may be too, as a faculty person!). I teach this activity during the third quarter of a three-quarter-long General Chemistry series, but I focus on contacting representatives with those students who take the first and second quarter of this class with me; thus, some students come to this activity with experience and other students, who are new to my General Chemistry courses, do not come with any experience. 

This activity aims to prepare many different students to contact elected official, regardless of their experience of contacting public officials prior to taking this class with me. Even after the class discussion in Step 7, some students do not want to send their email. As a result, I do not require students to send their email if they do not want to send it or feel uncomfortable about sending it, but I do ask them to explain to me why they do not want to send it and to explain the feelings that they have about contacting their public representative.

In the past, I have only required sending the letter when it is to a representative who has asked for community feedback on a specific issue. . For example, in 2023 a Kelp and Eelgrass Health and Conservation Plan was being developed in Washington (WA) state. The WA state Department of Natural Resources (DNR) had requested feedback from different stakeholders and community members. I had initially thought I could ask students to write to the DNR using an online feedback forum, which was not available, but the Commissioner's Office had a request for feedback over email. I asked students to give feedback over email and to send a blind copy to me to receive full credit. This was after students wrote a peer-edited draft, discussed any hesitations they had, and then made changes with feedback from both their peers and me. Here is the grading criteria they were given for a "Complete" grade: Grading Criteria for Email.docx (Microsoft Word 2007 (.docx) 14kB Jun17 24)In this case, students earned credit for participation and formative assessments were made during the discussions; students received feedback on their drafts in person in small groups.For the written component, students received feedback about claims-evidence-reasoning formatting, their calculations, the strength of their evidence and the clarity with which they explained how the evidence supported their opinion. After all of this work and feedback, students felt ready to send their email message. I think you could do this either way in your classroom, requiring or not requiring students to send an email. A discussion session during class similar to Step 7 could help you gauge students' comfort level and make a decision from there.


Assessment

1. Use le Chatelier's principle to explain how a decrease in pH can affect CaCO3 solubility.

I assess this learning goal using Questions 1 through 4 in the Pre-Lab assignment (page 9 of the laboratory experiment handout) and Question 2 in the Conclusions section of the Post-Lab assignment. I also use formative assessment for this when students respond to Question 2(a) in Part 1 of the post-lab report discussion and peer review (Step 7).

2. Determine the amount of seawater analyzed in each trial after a serial dilution.

I assess this learning goal using the calculations students do for Question 5 of the Pre-Lab assignment and Question 3 in the Data Analysis section of the Post-Lab Assignment.

3. Perform a complexometric titration to calculate the concentration of calcium ions in a sample of water.

I assess this learning goal using the calculations students do for Question 3 in the Data Analysis section of the Post-Lab Assignment.

4. Represent results, and express relationships between them, in a data table that compares calcium ion concentration, pH, and mass% seashell loss in carbonated and non-carbonated seawater.

I assess this learning goal using the Results section of the post-lab report as well as Question 1 in the Conclusion section of the Post-Lab Assignment.

5. Identify groups that will be disproportionately affected by ocean acidification and climate change.

I use a formative assessment during Step 1 of this activity, after students have watched the "Olympic Coast as a Sentinel" documentary. During the discussion that follows that documentary, students answer this question: "How are the effects of ocean acidification disproportionately felt by indigenous communities?" I listen to their responses during this class discussion for formative assessment; it is also an opportunity for me to provide them with feedback on this learning goal.

6. Describe how indigenous knowledge can be used to improve shellfish growth by creating clam beds.

I assess this learning goal using Question 3 in the Conclusion section of the Post-Lab Assignment, as well as using formative assessment in post-lab discussion. I also use formative assessment for this when students respond to Question 2(b) in Part 1 of the post-lab report discussion and peer review (Step 7).

7. Explain the effects of ocean acidification on seashells using lab results as evidence.

I assess this learning goal using the parts of the email to representatives that students write for Part 2 of the Post-Lab report. There are a few places where I can provide formative assessment here, before their final letter is due, specifically when students first send me their draft letter prior to the class session during which Step 7 occurs, and also during the actual class session that occurs during that step, when students have small group discussions and when we come together as one group later in the class session to summarize our discussions.

8. Express scientific conclusions in a persuasive letter to a public representative using claim–evidence–reasoning formatting. 

I assess this learning goal using the same process as I use to assess Learning Goal 7. Because some students are uncomfortable sending the email (letter), I do not require them to send it if they do not want to send it or feel uncomfortable about sending it. I do ask them to submit their email to me, and explain to me why they do not want to send it and to explain the feelings that they have about contacting their public representative. See the explanation of this above in Teaching Tips.

9. Reflect on and share reactions and feelings about contacting an elected official. 

I assess this learning goal formatively during the post-lab discussion and peer review that occurs during Step 7, specifically using Questions 2 and 3 in Part 2 of the "Post-Lab Report & Email Class Discussion.docx" Word file.

References and Resources

Perera and Bopegedera, 2014, Laboratory Experiment Investigating the Impact of Ocean Acidification on Calcareous Organisms, Journal of Chemistry Education, American Chemical Society

Buth, 2016, Ocean Acidification: Investigation and Presentation of the Effects of Elevated Carbon Dioxide Levels on Seawater Chemistry and Calcareous Organisms, Journal of Chemistry Education, American Chemical Society

Lyman and Flemming, 1940, Composition of sea water, Journal of Marine Research

Soda stream (a low-cost and low-tech way to simulate the pH of an acidified ocean)

The Olympic Coast as a Sentinel (20-minute-long documentary)

Lecture about ocean acidification (12-minute-long lecture that I made)

Reviving Clam Gardens (seven-minute-long PBS video; PBS is the Public Broadcasting Service in the United States)

How to Message Your Lawmakers (a resources of the American Chemical Society)